The researchers found that 25 HZ cases and one postherpetic neuralgia case could be prevented for every 1,000 persons receiving the vaccine at age 50 years. For HZ vaccine versus no vaccine, the incremental cost-effectiveness ratio (ICER) was $323,456 per quality-adjusted life-year (QALY). Vaccine cost (at a value of $80) and the rate at which efficacy wanes were the only variables that produced an ICER less than $100,000 per QALY in deterministic sensitivity analysis. The mean ICER was $500,754 per QALY in probabilistic sensitivity analysis. The probability that vaccination would be cost-effective was 3% at a willingness-to-pay threshold of $100,000 per QALY.

"Herpes zoster vaccine for persons aged 50 years does not seem to represent good value according to generally accepted standards," the authors write. "Our findings support the decision of the Advisory Committee on Immunization Practices not to recommend the vaccine for adults in this age group."